General Solar Technical Information
Transcript of General Solar Technical Information
Fueling the Farm II
General Solar Technical Information
North Carolina Solar Center
Why Solar Heating?
p Attractivep Self-sufficient.
p Environmentally friendly.
p Saves Money $$$.
p Saves Energy - The Sun is Free.
The Solar Facts
p Effective surface temperature of 10,400 °F.
The Solar Facts
p The amount of sunlight that falls on North Carolina on a typical day is equal to the total amount of energy we will consumer this year.
The Solar Factsp The sun has been active for 4.6
billion years and has enough fuel for another 5 billion years, a sustainable energy source for many years to come.
The Solar Facts
p For each typical solar hot water system installed, there is a reduction of over 4,500 lbs of CO2emitted into our North Carolina air each year.
The Solar Facts
p For every 100 residential solar hot water systems installed in our state, approximately $25,000 will stay in the state each year and not leave for the purchase of electricity.
What are the general components to a solar water
heating system?
Solar Flat-Plate Collectors
p Absorber platepHousing
pGlazingp Insulation
Evacuated Tube Collectors
Heat Storage
Means of Heat Transfer
pFluid (Water or propylene glycol)pPumps (AC, DC or natural convection)pHeat Exchanger (None, internal or
external)
Controls
pDifferential ControllerpPV module
Solar Rating & Certification Corporation (SRCC)
p Independent third-party certification organization
pCollector certification (OG 100)pWater Heating System Certification (OG 300)pSolar Swimming Pool Heating (OG 400)
SRCC OG300 Systems
p Indirect Glycol(Heliodyne and SunEarth)pDrainback (Radco, Morley & Bobcat &
sun Solar Heating Systems)p Indirect Thermosyphon (Solahart)
Orientation, Slope and Shading
Solar Resource
Do We Have to Face South?
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South Southeast East Northeast North
Ann
ual E
nerg
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s (kW
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Which Way is True South
pMust take magnetic declination into account (In NC declination if 5-10 degrees W of South).
pFor Raleigh, true south is 7 degrees west of magnetic south.
What About Seasonal Changes?
Sun Position
Sun Position
Sun Position
So What About Slope?
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Horizontal (0º) 3/12 (14º) 4/12 (18.4º) 5/12 (22.6º) 6/12 (26.6º) 7/12 (30.3º) 8/12 (33.7º) 10/12 (39.8º) 12/12 (45º) Vertical (90º)
Ann
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nerg
y Sa
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s (k
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Orientation Effect on Annual Output
-90 -60 -30 0 30 60 90
015
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90Azimuth Angle
Slop
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Annual Angle Modifier vs. Orientation Raleigh, NC
95%-100%90%-95%85%-90%80%-85%75%-80%70%-75%65%-70%60%-65%55%-60%50%-55%
Fraction of Maximum
East WestSouth
Shading Can Be Critical
pShading can significantly reduce performance regardless of orientation.
pGood to conduct a site analysis.p Important to consider future growth of
surrounding trees.
Sun Chart
Orientation, Slope & Shading
pSouth facing, but OK +/- 45°pBest year round performance slope is
around latitude but most roof pitches will work.
pSpace heating will often require a steeper slope.
pA site with no shading is key. Make sure the solar window is open.
What Size System Do I Need?
pCollector rule of thumb:• 10 - 18 ft2 per person
pStorage tanks rule of thumb:• 1.5 - 2.0 gallons per ft2 of collector area
pSingle tank vs. preheat tank.• Single more efficient, while preheat is
generally more comfortable.
Tax Credit SummaryRenewable Technology Residential Non-residential
Biomass
35% $10,500 Per Installation
35% $2,500,000 Per Installation
Hydroelectric
35% $10,500 Per Installation
35% $2,500,000 Per Installation
Solar Energy Equipment for Domestic Water Heating
35% $1,400 Per Dwelling Unit
35% $2,500,000 Per Installation
Solar Energy Equipment for Active Space Heating
35% $3,500 Per Dwelling Unit
35% $2,500,000 Per Installation
Solar Energy Equipment for Combined Active Space and Domestic Hot Water Systems
35% $3,500 Per Dwelling Unit
35% $2,500,000 Per Installation
Solar Energy Equipment for Passive Space Heating
35% $3,500 Per Dwelling Unit
Solar Energy Equipment for Daylighting
35% $2,500,000 Per Installation
Solar Energy Equipment for Solar Electric or Other Solar Thermal Applications
35% $10,500 Per Installation
35% $2,500,000 Per Installation
Wind
35% $10,500 Per Installation
35% $2,500,000 Per Installation
Hot Water and Active Space Heating
pSystem must be installed by an appropriately licensed in NC contractor or, in the case of a residential installation by homeowner, in accordance with the North Carolina State building code and be inspected by a local code official.
pSystem shall provide adequate freeze protection, which does not rely on electrical power.
Hot Water and Active Space Heating
pSpace heating systems shall also provide adequate overheating protection during the non-heating season.
pThe system must include an easy to understand way for the owner to determine if the system is operating properly.
p It is highly recommended that installed solar collectors be OG-100 certified by the Solar Rating and Certification Corporation (SRCC).
pRecommend OG-300 for water heating.
For More Information...
Contact:Personal Taxes Division at
(919) 733-8510
or Corporate Excise & Insurance Tax Division at (919) 733-8510
For More Information...
Contact the NC Solar Center atwww.ncsc.ncsu.edu1-800-33-NCSUN